Saturday, February 28, 2009

The Yuck Factor and the Evolution of Moral Disgust

Conservatives often appeal to moral emotions such as disgust and anger as important for moral judgment. One example is conveyed in a phrase made famous by Leon Kass--"the wisdom of repugnance." If some proposed technique of biotechnology--such as cloning, for instance--elicits deep disgust in many of us, then, Kass suggests, this should be taken seriously as an expression of moral concern.

Kass's critics have rejected such thinking as irrational in allowing emotions to cloud our moral reasoning. After all, can't we easily think of many situations were feelings of disgust support immoral positions such as racism and anti-Semitism?

The defense of Kass's position has been hindered by the fact that Kass and his supporters have often failed to explain the philosophic and scientific tradition supporting the importance of moral emotions for moral judgments. As I have argued in a previous post, Kass's reasoning belongs to a tradition of moral naturalism that stretches from David Hume to Adam Smith to Charles Darwin--a tradition that recognizes the emotionality of moral experience and that denies that pure reason by itself can explain moral judgment.

Moral reasoning is important to moral judgment, because our moral emotions are responses to how we interpret the practical circumstances of life, and so we can reason ourselves into and out of our emotions depending on how we interpret those circumstances. As I have indicated in previous posts, the incest taboo illustrates this. Incest provokes deep disgust in the minds of most of us. But our individual reasoning and cultural learning influence what we consider to be incestuous behavior. Some people and societies regard cousin marriage as incest and thus disgusting. But those who conclude that cousin marriage poses very little risk of physical or mental disabilities in the offspring might feel no disgust with cousin marriage.

Now we have new research exploring the evolutionary and neurophysiological bases of moral disgust. The February 27th issue of Science has a research report by H. A. Chapman et al. entitled "In Bad Taste: Evidence for the Oral Origins of Moral Disgust" and a commentary by Paul Rozin et al. entitled "From Oral to Moral."

Here's the abstract for the Chapman article:

"In common parlance, moral transgressions 'leave a bad taste in the mouth.' This metaphor implies a link between moral disgust and more primitive forms of disgust related to toxicity and disease, yet convincing evidence for this relationship is still lacking. We tested directly the primitive oral origins of moral disgust by searching for similarity in the facial motor activity evoked by gustatory distaste (elicited by unpleasant tastes), basic disgust (elicited by photographs of contaminants), and moral disgust (elicited by unfair treatment in an economic game). We found that all three states evoked activation of the levator labii muscle region of the face, characteristic of an oral-nasal rejection response. These results suggest that immorality elicits the same disgust as disease vectors and bad tastes."

The logic of this reasoning turns on the principle of preadaptation--what evolves for one purpose can be used for another purpose. What originated as a system for rejecting bad food could be extended--through genetic or cultural evolution--to a system for evaluating some things or thoughts as disgusting and thus causing withdrawal from those disgusting things or thoughts.

This research confirms Darwin's insights in his book The Expression of the Emotions in Man and Animals. In the Descent of Man, Darwin had argued for an evolutionary theory of morality as rooted in a natural moral sense expressed in moral emotions or sentiments. Here he followed in the tradition of Hume and Smith, who argued that without the motivational power of moral emotions, pure reason alone could not explain moral judgments. Moreover, Darwin tried to show how these moral emotions could have arisen from primitive animal instincts. His book on the emotions was designed to show that there were some universal facial expressions of human emotions that suggested primitive origins shared with other animals. Expressions of disgust were one example of a universal pattern suggesting moral emotions.

This new research correlating specific facial muscle movements with the disgust felt when human beings think about unpleasant tastes, cockroaches, incest, or unfairness (in the "ultimatum game") suggests the evolutionary origin of disgust in distaste.

This could explain why Hume and others in the Scottish moral tradition emphasized the importance of "good taste" in moral experience as grounded in human nature.

When I was a graduate student at the University of Chicago in the mid-1970s, I attended one of the first classes that Kass taught there. It was a class on the moral and biological psychology of the passions. The reading list included Darwin's Expression of the Emotions, as well as Book 2 of Aristotle's Rhetoric and Descartes' Treatise on the Passions. I was writing a dissertation on Aristotle's rhetorical theory, and I was interested in how Aristotle developed the moral psychology of the passions in the Rhetoric. I was also interested in how Darwin's work could be seen as uncovering the biological roots of such moral psychology in evolved human nature. It was clear that Kass had similar interests in the possibility of a Darwinian ground for Aristotelian moral naturalism. This was reflected in Kass's first book--Towards a More Natural Science--which influenced my thinking about "Darwinian natural right."

But then in later years, Kass began to move away from Aristotelian and Darwinian themes as he turned more and more to biblical writings, which culminated in his book on Genesis--The Beginning of Wisdom. He seemed to look more to an biblical ethics of divine command rather than an Aristotelian/Darwinian ethics of human nature. And yet his talk about the "wisdom of repugnance" shows a glimmer of that earlier attempt to explore the natural roots of morality in moral emotions.

Friday, February 20, 2009

Darwinian Natural Right in Primitive Law

My conception of Darwinian natural right includes an account of law. A full account of social order requires a nested hierarchy of three kinds of order--natural order, customary order, and rational order--so that custom is constrained by nature, and reason is constrained both by custom and by nature. Law manifests these three levels of order. The proponents of natural law are correct in seeing that law presupposes the natural desires and capacities of human beings. The proponents of customary law are correct in seeing that law presupposes custom. And the proponents of positive law are correct in seeing that law in the strict sense is the stipulation of the lawmaker. In fact, law is the joint product of nature, custom, and stipulation.

Darwinian natural right assumes that natural law reflects the twenty natural desires that constitute human nature as shaped by genetic evolution: human beings generally desire a complete life, parental care, sexual identity, sexual mating, familial bonding, friendship, social status, justice as reciprocity, political rule, war, health, beauty, property, speech, practical habituation, practical reasoning, practical arts, aesthetic pleasure, religious understanding, and intellectual understanding. These natural desires constrain but do not rigidly determine the customary evolution of law. Within the constraints of natural desires and customary traditions, there is some freedom for the exercise of prudential judgment in stipulating legal decisions and rules.

Opponents of the natural law position argue that there is no evidence for a universal human nature shaping the history of law. Cultural relativists say that law is purely a product of customary traditions that vary radically across societies and across time. Legal positivists say that law is ultimately a product of some lawmaking power unconstrained either by nature or by custom.

The study of primitive law helps to clarify this debate, and I think it provides support for Darwinian natural right. Perhaps the best single study of primitive law is E. Adamson Hoebel's The Law of Primitive Man (published first in 1954 and reprinted in 2006 by Harvard University Press). Hoebel was an anthropologist specializing in legal anthropology. He was best known for his work on the law of the Cheyenne Indians.

In the first part of this book, Hoebel lays out his general theoretical approach to the study of primitive law. He identifies himself as a "functional realist" who studies the behavioral reality of legal practice, as opposed to the conceptual abstractions of natural law or positive law theories.

In the second part of the book, he has five chapters on law in five primitive societies (ranging from the simplest to the most complex): the Eskimos, the Ifugao (in the northern Philippines), the American plains Indians (Comanche, Kiowa, and Cheyenne), the Trobriand Islanders (of the northeast coast of New Guinea), and the Ashanti (on the Gold Coast of West Africa).

In the last part of the book, he offers some general conclusions about the relation of law to religion, the functions of law, and the evolution of law. Hoebel puts his study in the context of Darwinian evolution. "Man emerged from the subhuman, supersimian state a million and more years ago" (291). As compared with chimpanzees, who are intensely social animals, who even have some rudimentary capacity for cultural learning ("protoculture"), the earliest human ancestors used their uniquely human capacity for speech to develop cultural learning far beyond anything seen in other animals (7-8). Using comparative studies of primitive foraging societies in the nineteenth and twentieth centuries, combined with archeological and fossil evidence of human evolution, allows Hoebel to infer what Paleolithic human societies were like (290-91).

Hoebel proposes a "postulation theory of law." Every group or society is organized around a set of fundamental postulates or values that represent "a limited selection from the total of human potentialities, individual and collective" (17). For each primitive society that he studies, Hoebel surveys the anthropological studies and formulates the set of postulated values that constitute the legal culture for that society.

I would say that what Hoebel calls "the total of human potentialities" corresponds to what I would call "human nature." What Hoebel calls the "limited selection" from within these potentialities corresponds to what I would describe as custom and stipulation selecting from within the potentialities of human nature those values that seem adapted to the particular needs and circumstances of a particular society.

So, for example, there is a natural desire for property expressed in every human society. But the specification of what counts as property and of the rights and duties of property varies across societies. Property in land is often not important for nomadic people. But it is very important for those like the Ifugao who get most of their food from growing rice.

I identify political rule as one of the twenty natural desires. But it might seem that primitive societies have no structure of political rule because they have no governments. "The Eskimo is what some would call an anarchist," Hoebel observes. "He has no government in the formal sense" (81). But this lack of "formal" government still leaves open the possibility of "informal" rule.

My claim is that human beings are by nature political animals, because they naturally live in social systems that require (at least occasionally) central coordination. In civilized human communities, such as bureaucratic states, this centralized coordination is formal and enduring. But in primitive human communities, such as hunter-gatherer bands, this centralized coordination of society is informal and episodic.

The Eskimos show this in their following the leadership of headmen. Hoebel explains: "The headman possesses no fixed authority; neither does he enter into formal office. He is not elected, nor is he chosen by any formal process. When other men accept his judgment and opinions, he is a headman. When they ignore him, he is not. Headmen are those who can hunt and 'who by their extended acquaintance with the traditions, customs, and rights connected with the festivals, as well as being possessed of an unusual degree of common sense, are deferred to and act as chief advisers of the community.' Such are the germs of political authority among the rude societies of mankind" (82).

This is what David Hume had in mind when he described in his essay "Of the Origin of Government" how the "love of dominion" as rooted in the "principles of human nature" would motivate leaders in savage societies who get prestige from acting as dominant individuals, although this dominance would depend on the voluntary consent, or at least acquiescence, of the other individuals in the society. In this way, the Lockean idea of "original contract" really does explain the primitive origins of law and government, although the later history of government has been decisively shaped by war and conquest.

I see in Hoebel's study confirmation of most if not all of the twenty natural desires rooted in evolved human nature, because one can see these natural desires expressed in some form in all of these primitive societies.

One can see, for instance, in all of these societies the desire for sexual mating and the need for social regulation to manage the conflicts created by sexual competition. The most common cause of homicide is men fighting over women. And this requires elaborate customary norms for marital bonding and resolving disputes over sexual partners.

Similarly, the prohibition of incest is universal in these primitive societies, although there is variation as to what counts as incest because kinship is sociologically defined. This variation is constrained by what the Darwinian would recognize as the "Westermarck effect." The incest taboo is strongest within the nuclear family, because of the tendency to feel a sexual aversion towards those with whom one has been reared from an early age. But this effect is not so strong outside the nuclear family--as with cousins. This pattern is clear in Hoebel's book, which also shows that even primitive people have some awareness of the deleterious effects of inbreeding, and thus some of their customary norms of incest avoidance could be deliberately formulated (109-10, 118-19, 131, 183-86, 191, 239, 254, 264, 291, 303).

My blog posts on the Westermarck theory of the incest taboo can be found here and here. Some of the comments on the first post offer some fascinating personal testimony.

There is some question, however, as to whether the natural desire for intellectual understanding can be found in these primitive societies. One Eskimo said this to an anthropologist: "Too much thought only leads to trouble . . . We Eskimos do not concern ourselves with solving all riddles. We repeat the old stories in the way they were told to us and with the words we ourselves remember . . . You always want these supernatural things to make sense, but we do not bother about that. We are content not to understand" (69).

Does this suggest that the desire to understand does not show itself in primitive societies? After all, as I have indicated in my post on George Anastaplo's study of non-Western cultures, there is a lot to be said for the claim that science or philosophy arose first in ancient Greece along with the discovery of the idea of nature.

At the end of Darwinian Natural Right, I argue that the desire to understand can be explained as a product of evolution, although this requires moving through the higher stages of cultural evolution. We can see in some other animals the tendency to curiosity or playful exploration that is the natural root of the human desire to understand. But the fullest development of the theoretical life as devoted to understanding for its own sake is manifested only after the cultural invention of writing. Only then was symbolic thought brought under the control of analytic reasoning through formal logic and systematic reflection. Preliterate primitive societies cannot show that search for understanding that arises in literate civilized societies, which eventually leads to philosophy and science.

Some posts on related topics can be found here, here, and here.

Saturday, February 14, 2009

Adam Gopnik on Darwin and Lincoln

It is a remarkable coincidence that Charles Darwin and Abraham Lincoln were born on the same day 200 years ago--February 12, 1809. In some previous posts, I have suggested that this should lead us to think about the points of contact between these two men.

Many books are now being published in connection either with the Lincoln bicentennial or the Darwin bicentennial. But one book combines the two--Adam Gopnik's Angels and Ages: A Short Book about Darwin, Lincoln, and Modern Life (Knopf, 2009). Gopnik is an award-winning writer for The New Yorker; and, as one might expect, this book is wonderfully written. A short excerpt from the book has been published in the February issue of Smithsonian magazine, which can be found online.

Gopnik's main theme is that Lincoln and Darwin were alike in helping to shape the "moral modernity" of "liberal civilization" as based on democratic politics and scientific reasoning--"science and democracy, an idea of objective knowledge arrived at by skepticism and of liberty available to all" (14, 18, 21). Gopnik uses the term "liberalism" in such a broad sense that it encompasses both the political "conservative" in American politics as well as the political "liberal" (18).

According to Gopnik, the crucial change associated with Lincoln and Darwin is the move from a "vertical" view of human life to a "horizontal" one. This is the move from "angels" to "ages." Previously, human beings saw themselves as looking up to the divine realm and down on the subhuman creation. With modernity, they began to see themselves as living in history--looking back to the past and ahead to the future--so that they were neither set above the natural world nor striving towards the supernatural world.

I have learned a lot from reading Gopnik's book. In particular, he has helped me see more clearly than I have previously the importance of the distinctive writing styles of Lincoln and Darwin. I also agree with much of what Gopnik says about the "liberalism" of Lincoln and Darwin.

I also think there is great insight in Gopnik's observations about how Darwinian science recognizes (and even explains) the gap between general knowledge and individual experience. "Individual experience is not reducible to general laws, not because of some mysterious essence that defies scientific explanation but because the explanation, as Darwin saw, begins with the existence of the irreducible individual case" (200). As Gopnik sees, there's an emotional reality to this--our knowledge of the common experience of life gives us no understanding or consolation before our personal tragedies.

Gopnik makes some mistakes. For example, he says that Darwin referred to his idea of evolution by natural selection as a "theory" to set it apart from any theological explanation of origins (185-86). But, in fact, Darwin concludes THE ORIGIN OF SPECIES by comparing his "theory of natural selection" and the "theory of creation." Darwin did not deny that creationism was a "theory." He did deny that this theory was as well supported by evidence and reasoning as his theory.

As far as the general themes of Gopnik's book, I disagree on three points. I don't agree with Gopnik that the liberalism of Lincoln and Darwin requires atheism. I don't agree with Gopnik's ignoring Darwin's evolutionary explanation of morality. And I don't agree with Gopnik's claim that Darwin's science has absolutely no political implications.

Although he suggests that Lincoln was an atheist, Gopnik is forced to recognize the biblical character of Lincoln's rhetoric and the fact that Lincoln frequently--especially in the Civil War--invoked God and conveyed a providential view of history. Gopnik speaks of Lincoln's faith as "the most vexed question in all the Lincoln literature" (126). Gopnik's attempt to answer this question turns out only to be a restatement of the question.

The young Lincoln was an atheist, Gopnik indicates, but the older Lincoln had experienced too much grief from death in war and death in the family to accept the idea of a universe governed only by natural necessity (130). "He came increasingly to believe in Providence, but it was a Providence that acted mercilessly through history, not one that regularly interceded with compassion" (131). This was most evident in Lincoln's later speeches--most memorably in the Second Inaugural. Gopnik compares this to Karl Marx's "new religion of history."

Although Gopnik rightly notes the Old Testament style of Lincoln's later speeches, he does not notice that Lincoln quotes from Jesus in the Second Inaugural, which suggests the influence of New Testament Christianity on Lincoln's providential view of history.

Gopnik shows us that both Lincoln and Darwin were moved by their personal experiences with death--Lincoln's boy Willie, Darwin's girl Annie--"to seek some form of transcendence, some meaning beyond the human cycle of breathing and eating and dying, even while resisting the supernatural meanings of faith." They found this transcendence in the "mystical sense of the power of time--time the explanatory force, the justifying force that gives meaning to life by asking us to think in the very long term" (186-87). This "faith in deep time" supports Lincoln's "private mysticism touched by public secularism" and Darwin's "shining inward faith in tension with scientific skepticism" (188).

Gopnik concludes his book by saying that the "Darwin and Lincoln, along with all the other poets of modern life" can affirm "mystical materialism" or "intimations of the numinous." The "space between what we know and what we feel" allows us to believe in "angels and ages, and both at once" (202-204).

Doesn't this contradict Gopnik's assertion that the modern liberalism of Lincoln and Darwin is necessarily atheistic? Isn't Gopnik forced to admit that they both show a religious longing for transcendence? And doesn't this suggest that the modern life of liberal democracy and scientific reasoning cannot obliterate the natural human desire for religious understanding?

I am reminded of that most famous of modern atheists--a contemporary of Lincoln and Darwin--Friedrich Nietzsche. Lou Salome--Nietzsche's friend and love interest--noted that Nietzsche never succeeded in becoming a scientific atheist, because he could never shake off his religious longings. Like his Zarathustra, he became "the most pious of those who don't believe in God."

When Gopnik speaks of how the "poets of modern life" will give us "intimations of the numinous," I am reminded of Nietzsche's prediction that modern artists would cater to the yearning of modern people to feel religious emotions without the burden of having to believe religious doctrines.

By comparison with Lincoln and Nietzsche, Darwin often seems serene in his scientific rationalism. And yet, even Darwin speaks of the limits of reason in striving for ultimate explanations for why nature is the way it is. As he wrote in his Autobiography, "the mystery of the beginning of all things is insoluble by us."

My second point of disagreement with Gopnik concerns his silence about Darwin's evolutionary explanation of morality. When Gopnik comments on Darwin's early notebooks and The Descent of Man, he says nothing about how these writings show Darwin's preoccupation with explaining human morality. Darwin knew that there could be no complete science of human life that did not include a science of human morality.

But like many of the proponents of evolutionary psychology, Gopnik invokes the "fact-value" distinction in assuming a dualistic separation between moral values and scientific facts. Human morality cannot be explained scientifically through the study of natural facts, because morality arises from free human choices. "It might be true, for instance, that life is brutal and pointless, but we can choose to live as though it were otherwise. . . . we all choose to live as though what we are doing has meaning and purpose beyond the day and moment" (195).

Like the existentialist philosophers, Gopnik appeals to human freedom from nature as creating a realm of choice that cannot be accounted for by modern science. But then he never explains how this metaphysical dualism of human freedom and natural causality can be compatible with Darwin's science, and especially Darwin's science of morality as rooted in evolved human nature.

Darwin and Lincoln did not regard the immorality of slavery as merely a matter of free choice. After all, slaveholders could freely choose to believe that slavery was morally right. Darwin and Lincoln thought slavery was wrong because it was contrary to the natural moral sense.

My final point of disagreement with Gopnik concerns his denial that Darwinian science has any political consequences. He writes: "The truth is that Darwin implies no politics: one can be a passionate Darwinian and be of the far right, the right, the liberal center, the left, or even the far left; great Darwinians have been found all around the room" (192). In fact, Gopnik declares, Darwinism does not even imply a liberal politics, although it does imply a "liberal science" (197-98).

Is that really true? Gopnik says that "traditionally, it was leftists, and Marxists in particular, who, despite the allegiance of Marx to its master, were the most hostile to Darwinism" (190). In proposing a "Darwinian left," Peter Singer argues that Marxism was a utopian vision contrary to evolved human nature as studied by the Darwinian. He admits that a "Darwinian left" would have to be "a sharply deflated vision of the left, its utopian ideas replaced by a coolly realistic view of what can be achieved."

As I have argued in Darwinian Conservatism, much of this "deflated" leftism would be acceptable to conservatives, who have long assumed that conformity to human nature is a fundamental standard for good social policy. In his Darwinian Left, Singer recognizes this at the end of the book when he hopes for a "new kind of freedom" that might one day "take us beyond the conventional Darwinian constraints" in human morality and social life.

Doesn't this show that leftists like Singer can never fully escape the utopianism of the leftist tradition of thought? And doesn't it show that any such utopian vision must be contrary to our evolved human nature as confirmed by Darwinian science?

Friday, February 06, 2009

Debating Darwin at

The bicentennial of Darwin's birth has brought lots of media attention to the continuing debate over the scientific, moral, political, and religious implications of Darwin's theory of evolution.

For example, the March issue of Discover magazine has a good section on evolutionary topics, including an article by Karen Wright where I make a cameo appearance.

An interesting collection of short essays is at, the online edition of Forbes magazine. Hana Alberts has edited a package of essays by twenty authors--ranging from proponents of Darwinism like Lionel Tiger and Denis Dutton to creationist/intelligent design opponents like Ken Ham and John West. Unfortunately, the brevity of each essay--averaging about 700 words--means than none of the authors can achieve much depth. But still the diverse range in the essays captures much of the current debate over Darwinism.

My essay for this collection is entitled "We Are The Moral Animals."

I will comment briefly on a few of the essays, beginning with the advocates for Darwin and then turning to the critics.

Denis Dutton makes an interesting point about how Darwin's idea of sexual selection--as opposed to natural selection--implies teleology, because in choosing mates, human beings have exercised purpose and intention in shaping evolution by sexual selection. He concludes that "prehistoric decisions honed the human virtues as we now know them: the admiration of altruism, skill, strength, intelligence, industriousness, courage, imagination, eloquence, diligence, kindness and so forth."

Of course, this still does not support any kind of cosmic teleology. And as Michael Flannery indicates, Alfred Russel Wallace broke with Darwin and sought to provide for such cosmic teleology by arguing that the human mind or spirit manifested the workings of some cosmic intelligence. I would say that Darwinian science does allow for an immanent teleology, as I have argued in an
earlier post.

Helen Fisher claims that recent scientific evidence confirms Darwin's belief that some nonhuman animals feel romantic love. She goes on to distinguish four personality types rooted in four distinctive brain systems. There is probably something to this, but it is grossly oversimplified. We simply don't know how to correlate personality to brain structure. She seems to rely on brain scanning research. But she fails to acknowledge the speculative character of this research.

Owen Jones is one of the leading law professors applying evolutionary reasoning to the study of law. His essay here, however, is too vague to convey much about his reasoning. At the end of the essay, he implies that he takes the idea of the "naturalistic fallacy" for granted: science cannot tell us "what we should want to accomplish," but it can help us to get to where we want. As I have said in some previous posts, I don't find this persuasive, because I don't see why the "ought" should be put in some transcendent realm beyond science.

Leo Tilman tries to summarize his account of "financial Darwinism," which he has laid out in a new book. Applying evolutionary reasoning to economic history is intriguing. It has a long history going back at least to Joseph Schumpeter. I have some posts on this--particularly on Niall Ferguson's recent book on "the ascent of money." But Tilman is so vague in his writing that I can't figure out what he is saying.

Joseph Carroll's essay is a good, brief statement of "literary Darwinism," which has also come up in a few of my posts.

But what about the critics? Kathryn Tabb says that "intelligent design has maintained a purely negative agenda seeking to disprove science's ability to answer questions instead of offering new approaches within the naturalist framework." This observation is confirmed by the fact that all of the critics here--Ken Ham, John West, Michael Egnor, and Jonathan Wells--employ a purely negative rhetoric in that they attack Darwinian science without offering any positive alternative of their own. As I have often noted, this is the preferred rhetorical strategy for creationists and intelligent-design proponents.

Ham and West accuse Darwinian science of promoting racism. But this is an odd charge considering how dedicated Darwin was in his opposition to slavery, as indicated by Adrian Desmond's essay. Moreover, neither Ham nor West acknowledge that much of the support for slavery was rooted in biblical religion, a topic that I have explored in various posts.

As I indicate in my essay, the real motivation for opposing Darwinian science is the fear that it subverts morality, although this ignores the ways in which a Darwinian account of the natural moral sense supports morality. West shows this fear of the moral consequences of Darwinism. I have written many responses to West, one of which can be found here.

Wells offers his standard arguments for his claim that Darwin's theory is not supported by evidence. Some of my responses to him can be found here, here, and here.

That Discover magazine article by Karen Wright ("We All Live in Darwin's World") is now available online.